1.1.1 Trust and communicating uncertainty.

Communicating honestly about uncertainty can build public trust and increase the legitimacy and credibility of the decision making process [12]. Public trust in the messengers of pandemic health risk information is associated with their willingness to comply with measures to prevent infection [13,14]. The World Health Organisation (WHO) advises health authorities to be candid about risk, events and interventions and to be forthcoming about what is known and what is not [7]. However, the different types of uncertainty that have been communicated have different effects on trust. Gustafson and Rice [15] reviewed the experimental literature and found that communicating disagreements or conflict in science (consensus uncertainty) were most often associated with reduced credibility. Communicating technical uncertainty (e.g., probabilities) had positive or no effect on perceived credibility. The effect was mixed in relation to communicating scientific uncertainty, which had both positive and negative effects on perceived credibility.

1.1.2 Tradeoffs in decision making.

Several safety science theorists have outlined tradeoffs as an inevitable balancing act among all kinds of pressures and safety in hazardous systems [16–18], including healthcare [19]. Tradeoffs involve ambiguity over what constitutes the right answer. According to Gregory et al. [20] tradeoffs are usually difficult to communicate. Changes in one endpoint are often achieved at the expense of other goals, and the consequences of tradeoffs are often unclear to the decision makers. According to Gregory et al. [20] tradeoffs reflect issues that science cannot resolve; they depend on values in making decisions about risk. Little is known about the public behavioral effect of communicating tradeoffs on decision making in pandemics, yet Gregory et al. [20] and Norheim et al. [21] argued that tradeoffs should be transparent to foster trust.

1.1.3 Risk amplification.

The Social Amplification of Risk Framework (SARF) suggests that most health risk messages are sent through transmitters (e.g. media, messengers) which alter the original message by intensifying or attenuating some signals before passing them on [10]. SARF proposes that risk deemed less urgent by experts may be amplified by other transmitters; however, risk that experts consider less urgent may be attenuated. According to SARF, silence from experts and decision makers may breed fear and suspicion among those at risk and lead to risk amplification. Nevertheless, a moderate level of fear can mitigate the risk of a pandemic by encouraging behaviour that protects public health [22]. To minimise risk amplification, health risk communicators should avoid sensationalism, speculation and disturbing images [23].

1.1.4 Public engagement.

In the early 1980s, “lay” perspectives were perceived as fallible and subjective by communication experts and policy makers, and communication interventions aimed to align lay perspectives with those of the experts in a one-way approach. As the field of health and risk communication evolves, multi-way approaches to communication emphasising public engagement have largely replaced the one-way approach to communication [9]. The WHO advises health authorities to involve the public in decision making to ensure that interventions are collaborative and contextually suitable, thereby constituting a two-way approach [7]. There is growing awareness of the benefits of including patients and the public in healthcare. However, involvement needs to be conducted at an even wider system level, e.g., involvement in the design of public health communication [24].

3.1.1 Modes of virus transmission.

The experts’ emphasis on modes of virus transmission is related to a potential increase in people’s comprehension of why they should comply with recommendations to protect themselves from COVID-19. One necessary message to communicate was how droplets containing the virus could reach people within a metre of the person emitting the droplets. This message helps to reinforce the need to keep physical distance.

Experts from several fields insisted that the public needed to comprehend the concepts of incubation period and asymptomatic transmission, which they expressed as: “You can be contagious even if you don’t have symptoms. Non-symptomatic people can carry the disease without being aware of it. You cannot tell if a person is infected or not, so everyone needs to keep distance”.

At the time of data collection there was scientific uncertainty about the modes of virus transmission of the coronavirus. Experts in medicine highlighted that it was important to address this uncertainty by communicating the most dominant route of transmission to help people distinguish possible from the most probable way of transmission.

Some of the experts used the terms contact/surface transmission, droplet transmission and airborne transmission when communicating with the public. The experts agreed that there was not a clear distinction but rather a continuum between droplet and airborne transmission. Although one expert in medicine believed it was important to illustrate a continuum of droplets with different sizes and reach, another medicine expert communicated how temperature and humidity affected how long the droplets stayed in the air and thus increased the probability of virus survival, and therefore the chance of being infected.

Contact transmission was found to be difficult to explain, due to the scientific uncertainty, as people who received the message interpreted the same information in different ways; as deadly with the need to go to extremes or as a non-relevant risk.

Some of the medicine experts did not communicate airborne transmission to the public. They considered that communicating the topic could elicit excessive fear due to the scientific uncertainty related to airborne transmission and SARS-COV-2, and due to the high level of scientific/health literacy needed to comprehend how aerosols could stay in the air. The science expert described how creating mental images of the airspace around people by using analogies to water have been used successfully as a pedagogic tool:

People have rather vague ideas about the medium of air, and what it means to breathe at a distance of one metre. It spreads in the same way, as if you dip a teabag in a cup of water. Because there is no hole here, it’s compact matter…. These particles are carried through matter in the same way as if you had dropped a small wooden plank on the water surface (No. 12)

Experts who did not use the terms droplets, airborne and contact/surface transmission, believed they were too technical and ambiguous. Instead, they prioritised the conveying of clear messages; how people could protect themselves by washing their hands and keeping their distance, as exemplified by a communication expert for nationwide health risk communication:

We have not been completely oblique about how the virus infects, and new virus variants change how the virus behaves…We have not used the terms airborne, droplet and contact transmission so often. We have been more concerned with explaining what the best precautions to take to avoid being infected by the virus are…We have noticed that there is a great demand among the general public for information about the mode of transmission, but people are just as concerned about how to handle the infection. They want to know what to do (No. 10).

One of the communication experts pointed out that modes of virus transmission were not mentioned in their target group analysis of young people’s concerns and values, thus the topic was not included in their targeted communication to adolescents.

3.1.2 Virus and immunity.

The medicine experts believed that it was important to explain how a virus attaches itself to the cells and creates disease. Such mechanisms were important to increase peoples understanding of variant virus’ changes in transmission. The variants of the virus had different causes for their increased contagiousness; for example, a medicine expert explained how a virus which can be in the upper respiratory tract one to two days before the disease breaks out is extremely contagious. A communication expert believed that explanations of virus autonomy and multiplication were too complicated for most people to understand. The communication expert for nationwide health risk communication noted that they had included this information when communicating to the public, despite its complexity:

We have tried to explain that here is a part of this virus, this spike that attached better [SARS-COV-2 Spike Protein]. It is complex information, but we have really thought that it is important to try to give it anyway, so that people understand why we still ask them to keep distance, and maybe even keep more distance now, because the contagiousness in the virus variations is different to the first virus variant that we are familiar with (No. 10)

Medicine experts experienced that the public tended to perceive mutations of viruses as dangerous, and considered it important to communicate the message that mutations are a natural part of the virus’s life cycle. The virus spreads by becoming more contagious without killing its host. Thus, by mutating the virus becomes less lethal.

Experts from diverse fields considered it important to inform about the effects of vaccination on immunity and how vaccination affected the individual and the society. At the individual level, it was important to convey the message that “you can still be infected and infect others even if you are vaccinated, however the vaccine may limit the lethality of infection”. At the society level, reducing the risk of infection through herd immunity through mass vaccination was a relevant concept to communicate.

3.2.1 Infection prevention at the individual level.

Experts from various fields agreed that the basic infection prevention measures were the most important to communicate to the public: keep distance; wash your hands; stay at home and get tested if you show symptoms; limit your contacts; and what quarantine and isolation mean. The communication expert for nationwide health risk communication explained the importance of conveying core messages with clear instructions:

We have observed a rather surprising desire for clear messages…There is a much greater willingness to be told what to do in Norway than I was prepared for… It’s very special, and a little different from the risk communication theory that state that you should describe the risk and let people make their own decisions (No. 10).

However, the rules were difficult to enforce if people did not understand the underlying principles. Many of the experts insisted that the rationales for infection prevention measures were important to explain to the public. Explaining why people had to follow the rules, and being open about the evidence and the pandemic decision making, were considered important in the creation of trust.

The science and medicine experts considered it important to teach the public about probabilities, and to convey the message that “there are no clear boundaries between safe and unsafe distance, the larger distance you keep, the less probability you have for being exposed to infection”. According to the science expert:

It is important to emphasise that when you set a two-metre limit, it is not because there is a black-and-white limit that if you are 2 metres and 10 cm from someone, you are safe, and if you are 1 metre and 90 cm, then you are not. That’s silly. So, you have to trust people to use their common sense and understand that it is a question of probabilities in all of the rules and guidelines that exist (No.13).

3.2.2 Infection prevention at group level.

While the scientific evidence for infection prevention was more definitive at the individual level, higher scientific uncertainty was related to infection prevention at the group level, which often led to public debates in the media over whether or not the evidence supported lockdowns of specific activities. The medicine experts emphasised the need to communicate the risk of being physically close to others and engaging in activities that increased the expulsion of droplets containing the virus (e.g., singing, going to pubs and gyms) to increase people’s understanding of why those activities had been stopped. As the nationwide health risk communication expert emphasised:

It is not about whether it is correct to close that particular school or shopping centre or not, it’s about reducing the total contact frequency among individuals, and these choices will be implemented with a high level of uncertainty regarding their efficiency (No. 10).

To reduce the stigma of contracting COVID-19, the communication expert for nationwide health risk communication emphasised that “this virus does not differentiate between people”. However, some of the medicine experts at community and regional hospitals reported feeling trapped between safeguarding individuals’ right to privacy and satisfying the media’s need for information.

Experts emphasised that conveying a message of hope could help people remain motivated despite of social distancing. The medical experts emphasised supportive messages and acknowledging people’s compliance. A communication expert described tailoring different messages to different populations in the municipality by showing them activities they could do during lockdown:

We identified that people wanted the municipality to stop telling them what they could not do, but rather what they could do. People can be outdoors even if we are on red level, and we have to think about measures to support, that involves being outdoor (No. 6).

3.3.1 Solidarity.

Experts explained the importance of informing the public of the collective moral responsibility to protect others, appealing to Norwegians’ sense of solidarity. As the communication expert at the national level explained:

Initially we needed to bring the entire population to the same problem definition, because we need to share the problem. We explained that it was most dangerous for the oldest and groups with chronic diseases…This means that approximately 70 percent of the population should be careful to protect the remaining population, and that as an individual you get some tasks to do to protect someone else than yourself (No. 10).

However, appealing to solidarity was considered challenging, because the messages need to be understood by the whole population, including people who are not in a life or work situation where they can participate in the collective effort by keeping physical distance, and people who come from cultural backgrounds that have a different understanding and valuation of collective moral responsibility.

3.3.2 Control of the spread.

Experts from different fields stressed the need to communicate the risk of losing control of the spread. They stated that “while the pandemic risk is low for many individuals, it is high for society”. To express the risk to society, the experts reiterated the potential consequences and future scenarios, conveyed as: “The virus is highly contagious. Losing control of the spread of the virus, will lead to healthcare services becoming overloaded which makes the pandemic deadlier”.

The media often used the reproduction number (R-number) to describe the status of the spread. According to the science expert in biostatistics:

The reproduction number says something about the growth of the disease, so it is the speed with which the disease will grow, the number of infected people will grow. And if this number is above 1, then the epidemic is exploding, if it is below 1, it is under control and will disappear. So, it is a fundamental number that describes the current status, where are we now (No. 11).

However, many of the experts decided against mentioning the R-number in their public messaging, because of the risk of misunderstanding it. The R-number was considered too complicated to explain to the public due to the need to understand uncertainties, simplified assumptions, and exponential growth. Many of the experts believed that the R-number could result in a misleading picture of the pandemic.

The experts stated that explanations of the risk of losing control should be balanced with information empowering the population to control the spread. Descriptions of realistic risk scenarios needed to be balanced with messages of hope. It was just as important to convey the severity of the risk as it was to avoid creating panic. As the public health expert in community psychology stated:

If too much fear is triggered, I think some people will defend themselves and refuse to deal with it. You should neither make the message so dangerous that it becomes overwhelming, neither so harmless that people think it does not matter what they do. I think you cannot under- communicate the consequences. You have to get a balance there (No. 5).

Lastly, messages implying the risk of losing control needed to be balanced with messages strengthening people’s sense of control. As such, the medicine experts did not merely reveal the status of infected and hospitalised people, but also that “we have control” to ensure the public’s trust in healthcare delivery. The experts believed in creating situational awareness while offering specific advice on how to minimise their risk.

3.3.3 Risk tradeoffs.

Some experts believed that giving people insight into their dilemmas could improve the public’s understanding of management strategies for the pandemic.

The experts emphasised the significance of informing the public of the risk tradeoffs between primary and secondary consequences of the pandemic”. However, their perspectives on risk differed. The medical experts at hospital and regional level had low risk acceptance for the negative consequences of lockdown and isolation (e.g., increased mental illness among children and adolescents). Thus, they wanted all measures to be proportionate to the infection risk. Nevertheless, the public health expert in community emergency management had low risk acceptance for primary consequences of the pandemic, and thus communicated the importance of preventing the spread of the virus by implementing measures as early as possible:

It’s very difficult to use strict and invasive measures to prevent infection. You have to wait until the infection has spread. Different professional experts, health and emergency preparedness disagree. We [community emergency preparedness] believe it is not about spreading fear. It is about having a proactive approach around a potential hazardous situation in the future. It is difficult to communicate, because our message is often shot down by the central health authorities (No. 3).

The science and medicine experts contended that the risk tradeoff between being infected versus being vaccinated needed to be communicated. This tradeoff was difficult to express, especially at the individual level:

To communicate that vaccines are used when a virus is so dangerous that it is worth taking the risk of side-effects to avoid being exposed to the infection is challenging. Where is that threshold? There is no final decision on that… When is the intersection where your individual risk should actually take precedence over the best interest of society and herd immunity? It’s twisted. I try to communicate the dilemma. I do not have a definitive answer, because there is no definitive answer (No. 13).